During the production of tea extracts, certain substances are extracted from the tea leaves which are insoluble in cold water and result in a cloudy formation when the extract is added to cold water. Although these substances may be removed by cooling the hot aqueous tea extract to precipitate them, there is a loss of up to about 30% of the total tea solids if the precipitated portion is then discarded, thus leading to a substantial loss of normal flavoring and color components. In addition, selected vegetable components may be added to tea to produce various effects, taste and the like. In one instance hibiscus flower extract is added to improve clarity and in U.S. Pat. No. 4,357,361, hibiscus or other vegetable materials are employed to improve the solubility of the powder by first extracting the vegetable material and then using this extract in a further extraction of black tea.
It has now been found that by employing a co-extraction of a blend of the tea leaves and selected vegetable material at the same time rather than in series that in addition to the improved solubility sought by the prior art, the beverage prepared from such co-extraction has better acid stability, is clearer and has a more stable color over the shelf life of the product. While not wishing to be bound thereby, It is theorized that the co-extraction with the hibiscus or indeed any acidic herb results in an extraction at relatively acid pH. When the resulting extract is polished acid insolubles are removed thus resulting is improved clarity and acid stability in the finished beverage. In addition, the pH of the co-extract is about 4.0 which reduces the risk of microorganism growth during processing.
Accordingly, the present invention provides a process for the preparation of a tea beverage or a black tea extract which comprises contacting black tea leaves blended with a second vegetable material with water which has been preheated to 70.degree. F. to 140.degree. F., maintaining at this temperature for a time sufficient to achieve good contact of the leaf blend with the water, afterwards separating the aqueous extract from the solid material and either preparing a ready-to-drink beverage or drying the aqueous extract.